Editor’s Note: A different entry under the title ‘Environment and Human Rights’, written in April 2009 by the late Alan Boyle (1953–2023), appeared as part of the online Max Planck Encyclopedia of Public International Law until the publication of the current version in 2024. This new entry has been published at the same web address (URL) as the original entry. The original entry was also published in the 2012 print edition of the Encyclopedia (R Wolfrum (ed) The Max Planck Encyclopedia of Public International Law (OUP Oxford 2012) vol III, 446–55).

A.  Notion

1  Since the 1972 Stockholm Declaration first enunciated the ‘fundamental right to freedom, equality and adequate conditions of life, in an environment of a quality that permits a life of dignity and well-being’ (Principle 1 Stockholm Declaration of the United Nations Conference on the Human Environment; Stockholm Declaration [1972] and Rio Declaration [1992]), the interplay between human rights and environmental law has been the subject of a vigorous academic and intergovernmental debate (Shelton [1991]; Boyle and Anderson [eds] [1996]; Boyle [2007]; Francioni [2010]; Boyle [2012]; Knox and Pejan [2018]). In the following decades, international and regional law instruments have increasingly identified a healthy environment as a pre-condition for the enjoyment of human rights and, in turn, human rights as a tool to protect at least some environmental interests (Bratspies [2015] 55).

2  As a result of this process, extant human rights obligations, such as those concerning the rights to life, property, and health have progressively been ‘greened’ (Life, Right to, International Protection; Property, Right to, International Protection; Health, Right to, International Protection). At the same time, international and regional instruments have progressively recognized specific ‘access rights’ (Access to Information on Environmental Matters; Access to Justice in Environmental Matters; Public Participation in Environmental Matters). Finally, the notion of a self-standing right to a ‘satisfactory’, ‘healthy’, ‘sustainable’ environment has gradually emerged (Clean and Healthy Environment, Right to, International Protection). This entry considers these developments, with a view to ascertain the state of play concerning the evolving relationship between the environment and human rights in international law.

B.  The Greening of Human Rights

3  The ‘greening of human rights’ situates the environment within the framework of existing human rights law, with a focus on the protection of humans. Essentially, it involves an adaptation or extension of the extant rights—such as those to life, private life, and property—to encompass environmental considerations (Boyle [2007] 473). Throughout the decades, international and regional human rights bodies have produced a substantial body of practice concerning the environment. As a result of this well-established trend, human rights obligations and remedies are routinely invoked to complain about human rights violations resulting from environmental harms, based on the law of State responsibility (Shelton [2015] 91; Human Rights, Remedies). For example, the Council of Europe’s Manual on Human Rights and the Environment ([2022]; Council of Europe [COE])—now its third edition—distils the principles emerging from the decisions of the European Court of Human Rights (ECtHR) and of the European Committee of Social Rights established under the European Social Charter. Similarly, the Inter-American Commission on Human Rights (IACommHR) has collected the Inter-American system’s practice concerning indigenous and tribal peoples’ rights over their ancestral lands and natural resources (IACommHR [2009]).

4  In 2013, the United Nations (‘UN’) special mandate holder on the issue of human rights obligations relating to the enjoyment of a safe, clean, healthy and sustainable environment, John Knox, published the first global review of practice in this area (United Nations Human Rights Council [‘UN HRCouncil’] [2013] UN Doc A/HRC/25/53). His report mapped human rights obligations relating to the environment, based on the practice of the UN’s human rights bodies and mechanisms; global human rights treaties; regional human rights systems; and international environmental instruments (Human Rights, Treaty Bodies; Environment, Multilateral Agreements).

5  These regional and global reports demonstrate that extant human rights instruments already deal with environmental interests as a matter of course, in two main ways. First, adverse environmental conditions may affect the enjoyment of human rights and therefore the application of obligations to protect. Second, environmental harm, or risks thereof, may trigger the application of so called ‘procedural’ human rights obligations. Third, the protection of the environment may be a legitimate aim justifying interference with human rights.

6  Human rights bodies have long established that environmental harm can lead to breaches of the rights to life, or to the enjoyment of home and family life (see eg the following ECtHR cases: López Ostra v Spain [1994]; Fadeyeva v Russia [2005]; Giacomelli v Italy [2006]; Cordella and others v Italy [2019]; see also Family, Right to, International Protection; Privacy, Right to, International Protection). Public authorities may as a result be ordered to take measures to ensure that human rights are not seriously affected by industry and other hazardous activities, like the operation of waste storage facilities, gold mines, or the spraying of pesticides (see eg Öneryıldız v Turkey [ECtHR] [2004]; Tătar v Romania [ECtHR] [2009]; Portillo Cáceres v Paraguay [UN HRC] [2019]). State responsibility in this connection might arise from failure to adequately regulate or enforce legislation concerning private industry (see eg Fadeyeva v Russia; Taşkin v Turkey [ECtHR] [2004]; Mayagna (Sumo) Awas Tingni Community v Nicaragua Case [IACtHR] [2001]) but also to take adequate measures to prevent and contain harm associated with natural disasters (see eg Budayeva and others v Russia [ECtHR] [2008]). A sizeable body of case law concerns specifically environmental harms leading to violations of the right of indigenous peoples to enjoy their own culture under Art. 27 International Covenant on Civil and Political Rights (1966) (‘ICCPR’) and Art. 7 (4) ILO ‘Convention No 169 Concerning Indigenous and Tribal Peoples in Independent Countries’ (1989) (Environment and Indigenous Peoples; International Labour Organization [ILO]). The right to culture has been progressively linked with that to property, granting indigenous peoples specific protection against environmental harm associated with activities, such as forest logging and oil and gas extraction (see eg Maya Indigenous Community of the Toledo District v Belize [IACommHR] [2004]; Saramaka People v Suriname [IACtHR] [2007]; Social and Economic Rights Action Center and Center for Economic and Social Rights v Nigeria [ACommHPR] [2001] [‘SERAC and CESR v Nigeria’]; Cultural Life, Right to Participate in, International Protection).

7  Human rights bodies have equally established that environmental harm—or risks thereof—may trigger the application of procedural obligations originating from civil and political rights, namely the freedom to seek, receive, and impart information (Art. 19 ICCPR), to take part in the government and in the conduct of public affairs (Art. 25 ICCPR), and to access to justice (Art. 14 ICCPR). These rights have been progressively interpreted to include duties: (a) to assess environmental impacts and make environmental information public; (b) to facilitate public participation in environmental decision-making, including by protecting the rights of expression and association; and (c) to provide access to remedies. International human rights bodies have placed particular emphasis on the public’s right to access information about dangerous activities which pose a threat to life. In some cases, human rights bodies have articulated a specific duty to inform (see eg Guerra and others v Italy [ECtHR] [1998] para. 60; Öneryıldız v Turkey para. 90). Similarly, the decision-making process leading to measures of interference with the enjoyment of human rights must be fair and afford due respect for the interests of affected individuals (Taşkin v Turkey para. 118). The individuals concerned must also be able to appeal against any decision, act, or omission where they consider that their interests or their comments have not been given sufficient weight in the decision-making process (eg ibid para. 119). Human rights bodies have recognized indigenous peoples’ rights to benefit from the exploitation of traditionally owned lands and their natural resources and to free prior informed consent over decision making concerning said lands (as exemplified by Saramaka v Suriname paras 137 and 140).

8  Finally, human rights bodies have established that the protection of the environment may be a legitimate aim justifying interference with human rights. The obligation to protect human rights from environmental harm does not require the cessation of all activities that may cause any environmental degradation (UN HRCouncil [2013] UN Doc A/HRC/25/53 para. 53 [‘2013 Report’]). International and regional human rights bodies have found that the right to peaceful enjoyment of one’s property may be restricted if this is considered necessary for the protection of the environment on several occasions. States have discretion to strike a balance between environmental protection and other issues of societal importance, such as economic development and the rights of others (eg Hatton and others v United Kingdom [ECtHR] [2003] para. 98; Fägerskiöld v Sweden [ECtHR] [2008]). This balance, however, cannot be ‘unreasonable, or result in unjustified, foreseeable infringements of human rights’ (2013 Report para. 53). The African Commission on Human and Peoples’ Rights (ACommHPR) has noted that the egregious environmental harm suffered by the inhabitants of the Niger delta was the result of lack of ‘the care that should have been taken’ (SERAC and CESR v Nigeria para. 54). In this respect, national and international health standards may be particularly relevant (2013 Report para. 53). For example, the European Committee of Social Rights evaluated the danger posed by water pollution vis-à-vis the safety standards set by the World Health Organization (WHO) and other public bodies (International Federation for Human Rights [FIDH] v Greece [ECSR] [2013] paras 42–44, 148). The ECtHR has taken into account national and WHO health and safety standards in deciding whether States had struck a fair balance between environmental protection and other interests (Dubetska and others v Ukraine [ECtHR] [2011]). Another relevant factor in deciding whether an environmental law meets human rights obligations is whether it is retrogressive (2013 Report para. 56). The Committee on Economic, Social and Cultural Rights’ General Comment 14 on the Right to the Highest Attainable Standards of Health notes that, if States take deliberately retrogressive measures, they have the burden of proving that they first carefully considered all alternatives, and that the measures ‘are duly justified by reference to the totality of the rights provided for in the Covenant in the context of the full use of the State party’s maximum available resources’ (General Comment No 14 para. 32; Committee on Economic, Social and Cultural Rights [CESCR]).

9  The practice has prompted the UN special mandate holder to conclude that extant international human rights law already encompasses a set of obligations relating to the environment (2013 Report para. 79). These obligations include procedural obligations to assess environmental impacts on human rights and to make environmental information public, to facilitate participation in environmental decision-making, and to provide access to remedies. They also include substantive obligations to adopt legal and institutional frameworks that protect against environmental harm that interferes with the enjoyment of human rights, including harm caused by private actors (2013 Report para. 80). As noted above, the practice strongly indicates that although States undoubtedly have discretion to weigh environmental protection against other legitimate societal interests, such a balance should be reasonable.

10  These findings are echoed in subsequent human rights documents. For instance, the Human Rights Committee’s General Comment No 36 emphasizes that environmental degradation, climate change, and unsustainable development are significant threats to the present and future generations’ right to life (Human Rights Committee [‘UN HRC’]). It suggests that the obligations of States parties under international environmental law should influence the interpretation State obligations associated with the right to life. Additionally, States’ obligations to respect and ensure this right should ‘also inform their relevant obligations under international environmental law’ (UN HRC ‘General Comment No 36’ [2018] para. 62).

C.  The Rise of ‘Access Rights’

11  Inspired by Principle 10 Rio Declaration (1992), international and regional instruments have progressively recognized specific ‘access rights’ granting individuals and groups access to environmental information, decision-making processes and judicial remedies. Two dedicated international treaties have been adopted: the 1998 United Nations Economic Commission for Europe Convention on Access to Information, Public Participation in Decision-Making and Access to Justice in Environmental Matters (‘Aarhus Convention’) and the 2018 United Nations Economic Commission for Latin America and the Caribbean Regional Agreement on Access to Information, Public Participation and Justice in Environmental Matters in Latin America and the Caribbean (‘Escazú Agreement’).

12  What distinguishes these dedicated access rights from the greening of human rights reviewed above is their greater specificity and the focus on the environment (Boyle and Redgwell [2021] 309). The Aarhus Convention includes particularly detailed obligations on environmental information that must be provided to the public (Arts 4–5); on decision-making processes that must be open to the public (Arts 6–8); and on access to justice, including injunctive relief, that is fair, equitable, timely, and not prohibitively expensive (Art. 9). The Compliance Procedure of the Aarhus Convention has significantly contributed to design the contours of member States’ understanding of access rights (Samvel [2020]; Compliance Procedure: Aarhus Convention; Environmental Compliance Control). Many States have also reported detailed information concerning measures to implement their obligations under the Aarhus Convention as part of the Universal Periodic Review Procedure of the Human Rights Council (Universal Periodic Review Procedure: Human Rights Council; United Nations Commission on Human Rights/United Nations Human Rights Council). The Escazú Agreement builds and expands on the architecture designed with the Aarhus Convention, including new and specific provisions on indigenous peoples and other vulnerable groups, on the protection of environmental rights defenders, and on environmental information held by private parties (Arts 5 (4), 6 (9)–(13), and 9).

13  More generally, requirements concerning public participation and access to information are mentioned in a host of international treaties. The 1998 Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade (Art. 15; Hazardous Substances, Transboundary Impacts), the 2001 Stockholm Convention on Persistent Organic Pollutants (Art. 10; Persistent Organic Pollutants [POPs]), and the 1992 United Nations Framework Convention on Climate Change (‘UNFCCC’) (Art. 6 (a); Multilevel Climate Governance; Climate Protection Agreements), require that environmental information be provided to the public. Environmental treaties that provide for public participation include the Stockholm Convention on POPs (Art. 10), the 1992 Convention on Biological Diversity (Art. 14 (1); Biological Diversity, International Protection), the 1994 Convention to Combat Desertification (Arts 3 and 5; Desertification), and the UNFCCC (Art. 6 (a)). Finally, some international environmental instruments establish obligations for States to provide for remedies in specific areas. For instance, the 1982 United Nations Convention on the Law of the Sea requires its parties to ensure recourse to natural or juridical persons for prompt and adequate compensation or other relief for damage caused by pollution of marine environment (Art. 235; Law of the Sea).

D.  The Right to a Healthy Environment

14  The content and usefulness of a self-standing, independent right to a clean and healthy environment have been the subject of much intergovernmental and scholarly debate (Bratspies [2015]; Boyd [2018]; Knox and Pejan [eds] [2018]). In spite of the lack of an explicit recognition in the ‘foundational’ international human rights treaties, the right has made great strides since its first formulation in the Stockholm Declaration.

15  Many regional and specialized human rights instruments already recognize the right to a ‘satisfactory’, ‘healthy’, ‘sustainable’ environment as a self-standing right (Art. 21 African Charter on Human and Peoples’ Rights [1981]; Art. 11 Additional Protocol to the American Convention on Human Rights in the Area of Economic, Social and Cultural Rights [1988]; Art. 24 (2) (c) Convention on the Rights of the Child [Children, International Protection]; Art. 38 Arab Charter on Human Rights [2004]; Art 28 ASEAN Human Rights Declaration [2012] [Association of Southeast Asian Nations (ASEAN)]; and Art. 18 Protocol to the African Charter on Human and Peoples’ Rights on the Rights of Women in Africa [2003]; Women, Rights of, International Protection). These instruments treat the right to a healthy environment as a cultural, economic, and social right, or as collective or solidarity right, giving ‘peoples’ rather than individuals a right to determine how their environment and natural resources should be protected and managed (Solidarity Rights [Development, Peace, Environment, Humanitarian Assistance]; Conservation of Natural Resources). At the time of writing, the Council of Europe is also considering the adoption of a dedicated instrument to anchor the right to a healthy environment in the human rights system created with the European Convention for the Protection of Human Rights and Fundamental Freedoms (1950).

16  Since 2012 the HRCouncil has adopted a series of resolutions titled ‘Human Rights and the Environment’. Amongst others, these resolutions created a special mandate on the issue of human rights obligations relating to the enjoyment of a safe, clean, healthy, and sustainable environment. The mandate holders—John Knox (2012–2018) and David Boyd (2018–2024)—have studied the obligations associated with this right (UN HRCouncil [2016] UN Doc A/HRC/31/52 [‘2016 Report’]; UN HRCouncil [24 January 2018] UN Doc A/HRC/37/59; UN HRCouncil [19 July 2018] UN Doc A/73/188 [‘2018/2 Report’]) and identified good practices (UN HRCouncil UN Doc [2019] A/HRC/43/53). Their reports suggest that the right contributes to the improved implementation and enforcement of environmental laws (2018/2 Report para. 55). They furthermore suggest that this right helps to provide a safety net to protect against gaps in environmental laws and creates opportunities for better access to justice (ibid para. 41). The rapporteurs conclude that, were the Universal Declaration of Human Rights (1948) to be drafted today, it would certainly include the right to a healthy environment (2018/2 Report para. 37).

17  In 2021 and 2022, the HRCouncil and the United Nations General Assembly (‘UNGA’) adopted resolutions acknowledging the ‘right to a clean, healthy, and sustainable environment’ as an independent human right (UN HRCouncil Res 48/13 [2021]; and UNGA Res 76/300 [2022] respectively; United Nations, General Assembly). While formally not legally binding, these resolutions may be viewed as part of a process whereby, pursuant to the principle of systemic integration, international bodies exhort States to interpret obligations on human rights and the environment in a mutually supportive fashion (Savaresi [2021]).

18  Yet, international jurisprudence based on the right to a healthy environment remains relatively scarce. The ACommHPR was the first international human rights body to find a violation of this right. In SERAC and CESR v Nigeria it held that Art. 24 of the African Charter on Human and Peoples’ Rights imposes an obligation on the State to take reasonable measures ‘to prevent pollution and ecological degradation, to promote conservation, and to secure ecologically sustainable development and use of natural resources’ (ibid para. 52). According to the Commission, this obligation encompasses the clean-up of environmental harm, the preparation of environmental and social impact assessments, and provision of information on health and environmental risks and meaningful access to regulatory and decision-making bodies (ibid ‘Holding’).

19  In 2017, the Inter-American Court of Human Rights (IACtHR) adopted an advisory opinion on The Environment and Human Rights (Advisory Opinion OC-23/17). The advisory opinion recognizes the right to a healthy environment as an autonomous and justiciable right within the Inter-American system. In Indigenous Communities of the Lhaka Honhat (Our Land) Association v Argentina (2020) the Court relied on its advisory opinion, to issue its first judgment finding a breach of the right to a healthy environment. The judgment articulates the States’ obligation to protect this right and prevent violations, including duties, such as those of conducting environmental impact assessments, and mitigating damage to the environment once it occurred (para. 208; Environmental Impact Assessment).

20  The right to ‘an ecologically sound environment’ is also incorporated in the Global Pact for the Environment (UNGA Res 72/277). The pact is a draft international treaty designed to acknowledge a new generation of fundamental rights and duties related to environmental protection (Young [2018]; Kotzé and French [2018]). The negotiation of this treaty was initiated by the UN General Assembly in 2018, receiving 143 votes in favour, 5 votes against, and 7 abstentions (UNGA ‘Draft Resolution: Towards a Global Pact for the Environment’). However, in 2019, States opted for the adoption of a political declaration, marking a setback to the initial ambition to establish a legally binding international treaty (UNGA Res 73/333).

21  More recently, increasing attention has been paid to the rights of nature, as a means to address extant governance shortcomings and better cater for environmental interests (Nature, International Protection). The movement towards the recognition of the rights of nature stems from awareness of the trade-offs between environmental and human rights protection and the caveats associated with the inherently anthropocentric approach embedded in the greening human rights described above (Tănăsescu [2020]; Petersmann [2021]). In some States—including Bolivia, Bangladesh, Colombia, Ecuador, India, New Zealand, Spain, and Uganda—national, regional, or local law or case law already ascribe legal personality and rights to natural resources, like rivers or forests (UN Environment Programme [‘UNEP’] [2023] 115). Civil society has strongly advocated for the recognition of the rights of nature. For example, the Earth Charter (2000)—a civil society initiative, with no formal status in international law—recognizes that ‘all beings are interdependent and every form of life has value regardless of its worth to human beings’ (Principle 1).

E.  Climate Change and Human Rights

22  While the debate on human rights and the environment has spanned well over five decades, it has found renewed impetus in the face of the challenges posed by climate change. Climate change is set to affect the enjoyment of virtually all human rights (UN HRCouncil [2019] UN Doc A/74/161 paras 26–51). At the same time, climate change response measures—especially those constraining access to and use of natural resources—may themselves hinder the enjoyment of several human rights (2016 Report paras 50–68; UN HRCouncil [2022] UN Doc A/77/226 paras 16–25). The preamble of the Paris Agreement (2015) recognizes this state of affairs, specifying that States ‘should, when taking action to address climate change, respect, promote and consider their respective obligations on human rights’ (Savaresi [2018]). Since 2009, the HRCouncil has adopted a series of resolutions titled ‘Human Rights and Climate Change’ and appointed a special mandate holder (UN HRCouncil Res 48/14; Special Procedures: Human Rights Council).

23  International human rights bodies have progressively articulated the implications of States’ human rights obligations concerning climate change (Center for International Environmental Law [‘CIEL’] [2023]). At the same time, national and international judicial and quasi-judicial bodies are increasingly asked to hear complaints concerning climate change and its impacts (Savaresi and Setzer [2022]; Rodríguez-Garavito [2022]). Applicants in these complaints routinely invoke State responsibility for breaches of international obligations concerning the protection of human rights (Savaresi [2023]).

24  At least in principle, international human rights bodies provide avenues to enforce States’ international obligations on climate change and put pressure on States to make good of the pledges they made. So far, however, international human rights bodies have rejected the majority of climate complaints they received, due to lack of exhaustion of domestic remedies, jurisdiction, or compliance with victimhood requirements (Luporini and Savaresi [2023]; see eg Committee on the Rights of the Child ‘Communication No 104/2019, Sacchi and others v Argentina’ [2021]’; Committee on the Rights of the Child [CRC]).

25  The only international human rights body to have issued a decision finding in favour of climate applicants is the Human Rights Committee (UN HRC ‘Communication No 3624/2019, Billy and others v Australia’ [2022]; ‘Torres Strait Islander case’). The Committee found that Australia had failed to comply with its positive obligation to adopt ‘timely adequate’ adaptation measures to protect the applicants’ home, private, and family life, their collective ability to maintain a traditional way of life, and to transmit their customs and culture to future generations (paras 8.9–8.14). However, the Committee did not find a violation of the right to life, as the applicants had not demonstrated a concrete and reasonably foreseeable risk to which their life would be exposed to, or shown the effects that climate change had already had on their health. The Committee emphasized that, in the period of time in which the islands would allegedly become uninhabitable, Australia could undertake preventative measures and, if necessary, relocate the applicants (ibid para. 8.7).

26  This situation makes it difficult to assess the role played by international human rights bodies in climate litigation. Arguably, complaints before international human rights bodies have put a ‘human face on climate change’ and pioneered a combination of scientific evidence, legal argumentation, and testimonies that has been replicated by climate litigants all over the world (Luporini and Savaresi [2023] 9) (Scientific Evidence: International Adjudication). At the same time, international human rights bodies are also being used to articulate grievances challenging laws, projects, and policies aimed at delivering climate action, questioning the distribution of risks and impacts of climate action, as well as its implications on access to resources and the modalities of the transition process (Savaresi and Setzer [2022] 13).

27  States’ obligations on climate change are currently at the centre of three separate advisory opinions before three international courts: the International Tribunal for the Law of the Sea (ITLOS); the International Court of Justice (ICJ); and the IACtHR. Especially the latter two advisory proceedings are expected to elucidate the interpretation of States’ obligations under human rights law (Savaresi [2023]). These developments are particularly relevant for climate litigation before domestic and regional courts, where arguments regarding breaches of international obligations concerning climate change are increasingly prevalent (ibid). The outcomes of these advisory proceedings are likely to directly impact pending cases before international human rights judicial and quasi-judicial bodies, including the ECtHR (Hartmann and Willers [2022]; Pedersen [2023]).

F.  Assessment

28  Since the Stockholm Conference, a vast body of international practice on the interplay between environmental and human rights law has developed. At the beginning, this practice was largely confined to the ‘greening’ of extant human rights, which were interpreted in ways that are sympathetic to the protection of at least some environmental interests. As this entry has shown, the practice on this subject matter is abundant, consolidated, and truly global. The recognition of access rights that are procedural in nature is well-established in international legal practice, while the recognition of an autonomous self-standing right to a healthy environment is making great strides. So even though human rights treaties are not designed to protect the environment—and only some expressly guarantee a right to a safe, clean, healthy, and sustainable environment—in practice the unique supranational remedies they provide are frequently used to bridge the compliance and accountability gaps in environmental governance. And although international human rights bodies have limited enforcement powers, their practice has influenced domestic courts, contributing to setting the contours of States’ obligations in this area. The interaction and cross-fertilization between human rights and environmental law has never been more intense, and, as the body of international practice reviewed in this entry suggests, it is here to stay.